1. A solution of magnesium hydroxide is prepared by dissolving 361.824 mg of Mg(OH)2 in 273.5 mL of water. What is the equilibrium concentration of OH- in this solution?
For magnesium hydroxide, Ksp = 7.1 x 10-12.
Assume no volume change.

2. The above solution is filtered to remove all undissolved magnesium hydroxide solid. What mass of solid Mg(OH)2 should be recovered from the solution?
Express your answer in units of mg.

3. After the above solution was filtered and all undissolved magnesium hydroxide solid removed, 564.1 mg of tin chloride is added.
SnCl2 completely dissociates in aqueous solution. Hydroxide reacts with tin (II) to form a Sn(OH)2complex.
What is the equilibrium concentration of Sn2+ in this solution?
The formation constants for the tin-hydroxide complexes are: Kf1 = 2.5 x 1010, Kf2 = 3.2 x 1013.

4. What is the equilibrium concentration of the SnOH+ complex in this same solution?

5. What is the equilibrium concentration of Sn(OH)2 in this same solution?

6. What is the ionic strength of the above solution?

Liquid octane CH3CH26CH3 will react with gaseous oxygen O2 to produce gaseous carbon dioxide CO2 and gaseous water H2O. Suppose 94. g of octane is mixed with 161. g of oxygen. Calculate the minimum mass of octane that could be left over by the chemical reaction. Round your answer to 2 significant digits.

Liquid hexane CH3CH24CH3 reacts with gaseous oxygen gas O2 to produce gaseous carbon dioxide CO2 and gaseous water H2O. If 0.664g of water is produced from the reaction of 1.7g of hexane and 3.2g of oxygen gas, calculate the percent yield of water. Round your answer to 2 significant figures.

The activation energy for the reaction H2(g) + I2(g) ? 2 HI(g) is 167 kJ/mol, and ?E for the reaction is +28 kJ/mol. What is the activation energy for the decomposition of HI?

CH4 + O2-----CO2 +2H2O suppose 2.8 mol methane is allowed to react with 3 mol of oxygen A) what is the limiting reactant? B) how many moles of CO2 can be made from this mixture? How many grams of CO2?

Describe how the solvents worked as the mobile phase of the liquid chromatography experiment. Why was it necessary to use different concentrations of aqueous isopropanol in the step-gradient separation?

A solution is prepared from 4.5750 g of magnesium chloride and 43.248 g of water. The vapor pressure of water above this solution is found to be 0.3626 atm at 348.0 K. The vapor pressure of pure water at this temperature is 0.3804 atm. Part A Find the value of the van't Hoff factor i for magnesium chloride in this solution. Express your answer using four significant figures.

Assuming the water sample has a pH of 7.2, determine the amount of HOCl and OCl- in mg/L contained in the free chlorine residual of the treated sample.

A 26.9 mL sample of 0.373 M triethylamine, (C₂H₅)₃N, is titrated with 0.310 M hydroiodic acid.

The pH before the addition of any hydroiodic acid is .  

Use the Tables link in the References for any equilibrium constants that are required.

A 20.6 mL sample of 0.337 M ammonia, NH₃, is titrated with 0.229 M hydrochloric acid.

At the equivalence point, the pH is .

Glycolysis

1)describe the Schiff-base role in aldolase

2)Describe the role of the thioester intermediate in G3P dehydrogenase

3) Describe the differences between glucokinase and hexokinase

4) Describe the reactants/products/regulation for the three irreversible reactions in glycolysis (1, 3, 10)

Part A

Consider the second-order reaction:

2HI(g)→H2(g)+I2(g)

Rate law: k[H]^2

k= 6.4*10^-9 (mol*s) at 500 K

Initial rate = 1.6 * 10^-7 mol (l*s)

What will be the concentration of HI after t = 3.65×10¹⁰ s ([HI]t) for a reaction starting under this condition?

Part B

In a study of the decomposition of the compound X via the reaction

X(g)⇌Y(g)+Z(g)

the following concentration-time data were collected:

Given that the rate constant for the decomposition of hypothetical compound X from part A is 1.60 M−1⋅min−1, calculate the concentration of X after 14.0 min .

Part C

The following data were collected for the rate of disappearance of NO in the reaction 2NO(g)+O2(g)→2NO2(g):

What is the rate of disappearance of NO when [NO]= 6.15×10⁻² M and [O2]=1.75×10⁻² M ?

Part D

What is the rate of disappearance of O2 at the concentrations given in part (c)?

Part E

A certain reaction with an activation energy of 175 kJ/mol was run at 515 K and again at 535 K . What is the ratio of f at the higher temperature to f at the lower temperature?

Use f=e^−Ea/(R⋅T)

A) A 52.0-mL volume of 0.35 M CH3COOH (Ka=1.8×10−5) is titrated with 0.40 MM NaOH. Calculate the pH after the addition of 17.0 mL of NaOH.

B) Calculate the molar solubility of lead thiocyanate in 1.00 M KSCN. Lead thiocyanate, Pb(SCN)2 has a Ksp value of 2.00×10−5.

C) Calculate the molar solubility of AgBr in 0.10 M NaBr solution.

D) Calculate the molar solubility of Ni(OH)2Ni(OH)2 when buffered at pH=pH= 10.2. The Ksp of nickel hydroxide =6.0×10−16 M

A 1.38 L buffer solution consists of 0.193M butanoic acid and 0.350 M sodium butanoate. Calculate the pH of the solution following the addition of 0.0680 of NaOH. Assume that any contribution of the NaOH to the volume of the solution is negligible. The Ka of butanoic acid is 1.52×10−5.

Determine the limiting reagent and calculate the theoretical yield if 0.96 g of benzyltriphenylphosphonium chloride is reacted with 0.30 mL of cinnamaldehyde.  

This is from an experiment simulating a breathalyzer. Potassium dichromate standard is 0.625 mg/mL in 9M sulfuric acid. We are using the equation 3 C2H5OH + 2 K2Cr2O7 + 8 H2SO4 → 3 CH3COOH + 2 Cr2(SO4)3 + 2 K2SO4 + 11 H2O for the reaction of dichromate and ethanol.

Operating wavelength : 436 nm
Absorbance of solution 1 (10.0 mL Standard Dichromate and 1.00 mL H₂O) : 0.577 a.u.
Absorbance of solution 2 (10.0 mL Standard Dichromate and 1.00 mL ethanol standard) : 0.445 a.u.
Absorbance of solution 3 (10.00 mL Standard Dichromate and 1.00 mL simulated ethanol DWI sample) : 0.438 a.u.
Mass of dichromate in Solution 1 : 6.25 mg
Mass of dichromate in Solution 2: 4.820 mg
Mass of dichromate in Solution 3: 4.744 mg

For solutions 2 and 3, what is the mass of dichromate consumed, the moles of dichromate consumed, the moles of ethanol consumed, and the mass of ethanol consumed?